The U.S. Preventive Services Task Force has issued a recommendation that clinicians screen all adults for obesity and offer obese patients intensive counseling and behavioral interventions to promote sustained weight loss or refer them to other clinicians for these services. These recommendations are published in the December 2 issue of the Annals of Internal Medicine.
Obesity is associated with many significant health problems, including high blood pressure, diabetes, heart disease, premature death, and decreased quality of life. Health care providers should screen for obesity using the body mass index (BMI), which the Task Force said is a valid and reliable screening test. People with a BMI between 25 and 29.9 are considered overweight, and those with a BMI of more than 30 are considered obese. BMI is calculated either as weight in pounds divided by height in inches squared multiplied by 703, or as weight in kilograms divided by height in meters squared. An online BMI calculator can be found at http://www.cdc.gov/nccdphp/dnpa/healthyweight/assessing/bmi/adult_BMI/english_bmi_calculator/bmi_calculator.htm.
Clinicians also may consider measuring patients for centrally located body weight, which is independently associated with cardiovascular disease, using waist circumference as a measure. Men with a waist circumference greater than 40 inches and women with a waist circumference greater than 35 inches are at increased risk for cardiovascular disease, but these measurements may be inaccurate for people with a BMI greater than 35.
The Task Force defined intensive counseling for obese patients to include two or more individual or group diet and exercise counseling sessions per month for at least 3 months. Long-term maintenance interventions following initial weight loss can help sustain weight loss over time. According to the Task Force, counseling is more effective in helping people lose weight if combined with behavioral interventions that assist them in developing skills, motivation, and support systems. Primary care clinicians have an important role in diagnosing obesity and in either providing intensive counseling and behavioral interventions or referring patients to receive these services, according to the Task Force. Health plan coverage and the use of professionals in other disciplines may help facilitate these interventions.
For obese adults, the Task Force found insufficient evidence to recommend for or against the use of moderate or low intensity counseling, which they defined as monthly or less frequently, to promote sustained weight loss. For adults who are overweight but not obese, the Task Force found insufficient evidence to recommend for or against the use of counseling of any intensity or behavioral interventions to promote sustained weight loss. The Task Force did not make a recommendation about screening for obesity in children at this time because the topic is considered so important that it is being reviewed separately for a future report.
Over the past 40 years, prevalence of obesity among adults in the United States has increased from 13 percent to 27 percent. The proportion of adults considered to be overweight has increased from 31 percent to 34 percent. Obesity is more common in women, but men are more likely to be overweight. Obesity is especially common in blacks, American Indians, Native Hawaiians, and some Hispanic populations.
The Task Force noted that prescription drug therapy and surgery, such as gastric bypass, can be considered for treating obese adults but only as part of a comprehensive program that also includes intensive counseling and behavioral interventions. Surgical guidelines from the National Institutes of Health restrict bariatric procedures to people with a BMI of 40 or greater and those with a BMI of 35 or greater who also have at least one other obesity-related illness. The Task Force noted that the long-term effectiveness and safety of drug therapy and surgery are unknown.
The Task Force, which is sponsored by the Agency for Healthcare Research and Quality, is the leading independent panel of private-sector experts in prevention and primary care. The Task Force conducts rigorous, impartial assessments of the scientific evidence for a broad range of preventive services. Its recommendations are considered the gold standard for clinical preventive services. The Task Force based its conclusions on a report from a team led by Kathleen McTigue, M.D., M.P.H., at AHRQ's Evidence-based Practice Center at RIT International-University of North Carolina.
For more information, see "Screening and interventions for obesity in adults: Summary of the evidence for the U.S. Preventive Services Task Force," by Dr. McTigue, Russell Harris, M.D., M.P.H., Brian Hemphill, M.D., M.P.H., and others, in the December 2, 2003, Annals of Internal Medicine 139(11), pp. 933-949.